Crawler crane and method for fine-tuning a basic operating position of such a crawler

ABSTRACT

A level-controllable crawler crane includes two crawler supports with rotating crawlers, which crawler supports are connected by a transversal bridge. A superstructure of the crawler crane includes a crane jib pivotable about a vertical axis and connected to the transversal bridge. A pivotable articulation connects the transversal bridge to the crane superstructure. At least one of the crawler supports is connected to the transversal bridge by a double link having a lower and an upper link. The lower link is articulated on the crawler support by a crawler support lower pivotable axis and on the transversal bridge by a transversal bridge lower pivotable axis. The upper link is articulated on the crawler support by a crawler support upper pivotable axis and on the transversal bridge by a transversal bridge upper pivotable axis. A drive pivots the links about the pivotable axis associated therewith.

FIELD

The invention relates to a crawler crane according to theprecharacterizing portion of claim 1. The invention furthermore relatesto a method for fine-tuning a basic operating position of such a crawlercrane.

BACKGROUND

A crawler crane of the type mentioned at the beginning is known from DE20 2006 002 023 U1. Booms of such crawler cranes can operate at theirnominal load only when the undercarriage with the crawler supports ispositioned on a plane that virtually does not deviate from thehorizontal. This requires a time-consuming and expensive preparation ofa basic operating position of the known crawler crane through gradingoperations.

SUMMARY

It is an aim of the present invention to improve a crawler crane of thetype mentioned at the beginning in such a way that the amount of timeand expense required for fine-tuning a basic operating position of thecrawler crane is reduced.

This aim is achieved according to the invention by a crawler cranehaving two crawler supports having rotating crawlers, at least onetransversal bridge connecting the two crawler supports, a cranestructure having at least one crane boom connected to the transversalbridge so as to be able to pivot about a vertical axis, a pivotarticulation that pivotally connects the transversal bridge to the cranesuperstructure, characterized in that at least one of the crawlersupports is connected to the transversal bridge via a double linkcomprising a lower link that is articulated via on the crawler support acrawler-support lower pivot shaft and on the transversal bridge via atransversal-bridge lower pivot shaft, an upper link that is articulatedon the crawler support via a crawler-support upper pivot shaft and onthe transversal bridge via a transversal-bridge upper pivot shaft, anadjustment drive for pivotally displacing at least one of the two linksabout the pivot shaft assigned to same.

In accordance with the invention it has been recognized that anundercarriage of the crawler crane with the two crawler supports in manycases can be set up in such a way that it has virtually no pitchinclination about a horizontal axis transverse to the driving direction,but only a roll inclination about an axis longitudinal to the drivingdirection. This roll inclination can be compensated via the double linkaccording to the invention. The adjustment drive can be designed to bemotor-driven, hydraulic or magnetic. It is also possible in principle tonot equip the adjustment drive with an adjustment motor of its own, butto drive the adjustment movement, for example, derived from anothermotor of the crawler crane or also from an external motor. In principle,a single such double link suffices, the other connections of the crawlersupports to the at least one transversal bridge then being capable ofbeing repositioned passively. It is preferred, however, when a pluralityof such double links are used. It is also possible, for example, toprovide per crawler support a plurality of such double links arrangedone after another in the driving direction. The adjustment drive can bedesigned compact with high power density and robustness.

An arrangement according to the claims in which both crawler supportsare connected to the transversal bridge via a double link having a lowerlink and an upper link, increases the stability of the crawler crane.

A plurality of drive-adjustable double links of both crawler supportsaccording to the claims, which have an adjustment drive for pivotallydisplacing at least one of the two links about the crawler-support pivotshaft assigned to same, improve the fine-tuning precision of a levelcontrol of the crawler crane.

A lower-link adjustment drive according to the claims in which the lowerlink is connected to the adjustment drive lowers the center of gravityof the crawler crane. A pivot shaft that is driven via the adjustmentdrive is then, in particular, the crawler-support lower pivot shaft.

The adjustment drive which has, according to the claims, a gear unit, inparticular a reduction gear, facilitates the connection and, ifapplicable, also the design of the adjustment motor.

A gear unit according to the claims in which at least three gear wheelsare provided that are in combing engagement with one another, the axesof rotation of which are parallel to one another, can increase adistance between a motor shaft of the adjustment motor and a componentof the double link driven by same, thereby simplifying the design of thedouble link.

An adjustment drive according to the claims which has a threaded rodconnected to the crawler support and a nut connected to the driven link,the nut being complementary to the thread of the threaded rod is robust.The nut can be designed self-locking. This self-locking behavior can becombined with a sensitive adjustability, thereby permitting a preciseinclination fine-tuning or leveling capability to be achieved. Throughthe design of the adjustment drive with the threaded rod and the nut, itis possible to derive from the rotational adjustment drive atranslational, low-backlash movement for an inclination fine-tuning, themovement monitoring of which is possible in a simple manner.

A threaded rod, which according to the claims has a trapezoidal externalthread and the nut which has a trapezoidal internal thread complementarythereto results in a self-locking of the adjustment drive. Additionally,such a trapezoidal thread has a high load-bearing capacity.

A driven threaded rod according to the claims in which the threaded rodis driven by the adjustment drive makes possible an adjustment drive,the design of which can be implemented with little time and expenditure.

A control device according to the claims is provided that is in signalconnection with the at least one adjustment drive, which permits theadjustment drive to be activated in particular from a cab of the crawlercrane.

An inclination sensor according to the claims is provided that is insignal connection with the control device, which makes possible aprecise inclination measurement. The inclination sensor can be acontactless magnetoresistive measuring element having a measuring rangeof +/−10%.

A regulating module according to the claims is provided that is insignal connection with the control device and with the inclinationsensor and provides to the control device positioning signals foradjusting the adjustment motor in such a way that if a roll inclinationof a foot print plane of the crawler support is present, the verticalaxis of the crane structure assumes a minimal angle relative to thevertical, makes possible an automatically regulated adjustment of theadjustment drive for level control of the upper structure of the crawlercrane.

A linear guiding mechanism according to the claims in which the nut isconnected via a linear guiding mechanism to the driven link makespossible a guided transmission of force between the nut and the drivenlink, while simultaneously creating the possibility of a high forcetransmission between the nut and the driven link. The linear guidingmechanism can be implemented by means of a plurality of bearing rollers.A bearing support for the linear guiding mechanism can be provided onboth sides of the nut. The linear guiding mechanism can support the nutin both directions of movement longitudinal to the threaded rod.

The advantages of a method according to the claimed invention correspondto those that have already been discussed above with reference to thecrawler crane according to the invention. The adjustment of theadjustment drive can be effected automatically regulated. This can beachieved, for example, by using the measured value from an inclinationsensor, such that the crane structure of the crawler crane maintains itsbasic operating position within a predefined permissible variation.

BRIEF DESCRIPTION OF THE DRAWINGS

An illustrative embodiment of the invention will be explained in moredetail below in conjunction with the drawing, in which:

FIG. 1 shows a side view of a crawler crane;

FIG. 2 shows a front view of an undercarriage of the crawler craneaccording to FIG. 1 together with components of a crane structure of thecrawler crane, certain boom elements of the crawler crane having beenleft out;

FIG. 3 shows a vertical section through a crawler support of the crawlercrane in the area of a double linkage thereof to a transversal bridge ofthe undercarriage represented by a broken line, a crawler of the crawlersupport being shown positioned on a horizontally extending groundsurface;

FIG. 4 shows the crawler support with the transversal bridge and thecrawler in an illustration similar to FIG. 3, with the crawler shownpositioned on an inclined ground surface, such that a roll angle of theundercarriage results that is different from zero;

FIG. 5 shows a detail view of a section of the crawler support from thedirection V in FIG. 3;

FIG. 6 shows, in even greater detail than FIG. 5, a nut as a componentof an adjustment drive for pivotally displacing a lower link of theundercarriage and thereby for a level-controlling of the crawler crane;

FIG. 7 shows an axial section through the adjustment drive in the areaof the connection of the nut according to FIG. 6 to a rotationallydriven threaded rod of the adjustment drive; and

FIG. 8 shows a section along line VIII-VIII in FIG. 7.

DETAILED DESCRIPTION

A crawler crane has a mobile undercarriage 2, an upper structure 3, amain crane boom 4 and a counter-boom 5. The upper structure 3 can rotaterelative to the undercarriage 2 about a vertical axis 7 by means of aroller slewing ring device 6, which is only intimated in FIGS. 1 and 2.

The undercarriage has two driven crawlers 8 that are supported andguided by means of two crawler supports 9 that are arranged parallel toone another. The two crawler supports 9 are connected to one another bymeans of a transversal bridge 10 or by means of a plurality of suchtransversal bridges. The at least one transversal bridge 10, in turn,carries the roller slewing ring device 6. The roller slewing ring device6 is a pivot articulation that connects the at least one transversalbridge 10 in a pivot-mounted fashion to the upper structure 3, that isto say to the crane structure.

The at least one transversal bridge 10 is connected at the two endsthereof to the respective crawler support 9 via a double link 11, whichis illustrated in detail in FIGS. 3 to 5. The double link 11 has a lowerlink 12 that is articulated on the crawler support 9 via acrawler-support lower pivot shaft 13 and on the transversal bridge 10via a transversal-bridge lower pivot shaft 14. Additionally, the doublelink 11 has an upper link 15 that is articulated on the crawler support9 via a crawler-support upper pivot shaft 16 and on the transversalbridge 10 via a transversal-bridge upper pivot shaft 17.

Both the lower link 12 and the upper link 15 have two identicallycontoured link plates that are arranged spaced apart one behind theother in the drawing plane of FIGS. 3 and 4 and fixedly connected to oneanother via shaft elements. The upper link 15 is reminiscent in theshape thereof of a chain link of a bicycle chain.

If a plurality of cross members 10 are present in the crawler crane 1,each cross-member end is connected to the facing crawler support 9 bymeans of such a double link 11.

The pivot shafts 13, 14, 16, 17 all extend parallel to one another andparallel to a foot print plane 18 that is defined by a bottom tread 19of the crawler 8 resting on the ground. In FIGS. 2 and 3 the foot printplane 18 extends horizontally. The crawler crane 1 and in particularalso the crawler supports 9 then neither have a roll inclination nor apitch inclination. In this non-inclined position of FIGS. 2 and 3, thetwo lower pivot shafts 13 and 14 of the double link 11 are onapproximately the same level. The transversal-bridge upper pivot shaft17 is slightly lower in this position than the crawler-support upperpivot shaft 16. In this position the crawler-support upper pivot shaft16 lies vertically above the crawler-support lower pivot shaft 13, andthe transversal-bridge upper pivot shaft 17 lies vertically above thetransversal-bridge lower pivot shaft 14. The mutual distance between thetwo lower pivot shafts 13, 14 is virtually equal to the mutual distancebetween the two upper pivot shafts 16, 17. The mutual distance betweenthe two crawler-support pivot shafts 13, 16 also is approximately equalto the mutual distance between the transversal-bridge pivot shafts 14,17 and corresponds to the distance between the lower pivot shafts 13, 14and the upper pivot shafts 16, 17.

Altogether, the four pivot shafts 13, 14, 16, 17 in the positionaccording to FIGS. 2 and 3 therefore lie approximately in the corners ofa square.

An adjustment drive 20 having an adjustment motor 21 serves forpivotally displacing the lower link 12 about the crawler-support lowerpivot shaft 13 and thereby for a level-controlling of the crawler crane1 to be described further below. Each of the double links 11 of thecrawler crane 1 can have such an adjustment drive 20.

The adjustment drive 20 has a threaded rod 22 that extends perpendicularto the foot print plane 18 and is connected to the crawler support 9 bymeans of an axial/radial bearing 23 fixedly connected to the crawlersupport, in a manner so as to be able to rotate about the longitudinalaxis of the threaded rod 22. The threaded rod 22 has an external threadthat is designed in the form of a trapezoidal external thread. A nut 24that is connected to the lower link 12 in a manner so as to be unable torotate relative to the crawler support 9, by means of connecting pieces25 that define a parallel key guidance runs on the threaded rod 22. Thenut 24 has a trapezoidal internal thread that is complementary to theexternal thread of the threaded rod 22.

The nut 24 is connected to a lever end 26 of the lower link 12, thelever end being located opposite the transversal-bridge lower pivotshaft 14. The crawler-support lower pivot shaft 13 lies between thelever end 26 and the transversal-bridge lower pivot shaft 14.

The adjustment motor 21 drives a rotation of the threaded rod 22 aboutthe longitudinal axis thereof by means of a gear unit 27 that isdesigned in the form of a reduction gear. The gear unit 27 has threegear wheels 28, 29, 30 that are in combing engagement with one another.The first gear wheel 28 is connected to a drive shaft 31 of theadjustment motor 21 so as to be integral in rotation with the driveshaft. The second gear wheel 29 serving as an intermediate gear isconnected by means of an axial/radial bearing 32 to the crawler support9. The third gear wheel 30 is connected to the threaded rod 22 so as tobe integral in rotation therewith. The number of teeth of the secondgear wheel 29 is greater than the number of teeth of the first gearwheel 28. The number of teeth of the third gear wheel 30 is greater thanthe number of teeth of the second gear wheel 29.

The adjustment motor 21 is in signal connection with a control device 34of the crawler crane 1 via a signal line 33. Connected to the controldevice 34 via an additional signal line 35 is an inclination sensor 36which, in turn, is mounted fixedly to the crawler support 9 and reads aroll inclination of the crawler support 9, that is to say an inclinationof same about an axis extending longitudinal to the driving direction.The control device 34 can have a regulating module 37 which likewise isin signal connection with the inclination sensor 36. The regulatingmodule 37 is designed as an internal component of the control device 34.Alternatively, the regulating module 37 can also be an externalcomponent that is in signal contact with the control device 34.

FIG. 4 shows a level-controlled position of the transversal bridge 10 ata foot print plane 18 of the crawler support 9 that is inclined relativeto a horizontal. A roll angle W between the foot print plane 18 and thehorizontal is 4°. In this inclined position of the crawler support 9 alevel control of the transversal bridge 10 is ensured by means of thedouble link 11 such that a transversal-bridge plane 38 and thereforealso the upper structure 3 has no roll inclination (W=0°) relative tothe horizontal.

In the position according to FIG. 4 the pivot shafts 13, 14, 16, 17assume approximately the positions of the corners of a rhombus. Thedouble link 11 thus has performed a parallelogram pivot movement fromthe position according to FIG. 3 to the position according to FIG. 4.

In order to fine-tune a basic operating position of the crawler crane 1the undercarriage 2 is first moved into a raw operating position. Thisraw operating position is selected such that the crawler crane 1 has nopitch inclination, that is to say no inclination of the foot print plane18 relative to the horizontal about an axis extending transversely tothe driving direction. Then, only the roll inclination needs to becompensated via the level control. The roll angle W of the respectivecrawler support 9 relative to the vertical is then measured with the aidof the inclination sensor 36. This roll inclination is communicated viathe signal line 35 to the control device 34. The regulating module 37calculates, for example via a calibration table, from the determinedroll inclination a positioning value for the adjustment motor 21. Thispositioning value is supplied to the adjustment motor 21 via the signalline 33. A rotational displacement of the threaded rod 22 by theadjustment drive 20 is effected accordingly in such a way that the nut24 assumes on the threaded rod 22 an axial position that corresponds toa predefined angle of pivot of the lower link 12 about thecrawler-support lower pivot shaft 13. According to this pivot angle thedouble link 11 moves into a level-controlled position in which thetransversal bridge plane 38 extends substantially horizontal despite theroll inclination of the crawler support 9 by the roll angle W. Thisensures a minimal angle of the vertical axis 7 of the upper structure 3relative to the vertical, such that the main crane boom 4 can supportthe nominal load thereof in a weight-balanced manner.

The adjustment of the adjustment drive 20 for the level control of theupper structure 3 can take place automatically regulated via theregulating module 37. Alternatively, it is possible for the inclinationsensor 36 to, for example, read a roll angle and for the operator of thecrawler crane 1 to carry out an appropriate fine-tuning of the doublelink 11 based on this roll angle via the control device 34.

Further details of the adjustment drive 20 for pivotally displacing thelower link 12 will be explained below in conjunction with FIGS. 6 to 8.

FIG. 6 shows the nut 24 in detail. The nut transforms the rotary motionof the driven threaded rod 22 into a linear movement longitudinal to thethreaded rod 22 (cf. double arrow 39). This linear movement 39 is thentransmitted to the lower link 12 by means of a guiding mechanism to bedescribed further below.

The nut 24 comprises a thread carrier 40, a thread insert 41 and a pairof bolts 42, 43.

The thread carrier 40 has an inner boiler plate 44 and an outer boilerplate 45 that surround the thread insert on the outside. The boilerplates 44, 45 each have bores 46 for accommodating the bolts 42, 43. Theboiler plates 44, 45 are held together both by a bottom sheet-metal ring47 and a top sheet-metal ring 48. The bottom sheet metal ring 47 has anouter circumference that corresponds to the outer circumference of theouter boiler plate 45. The bottom sheet-metal ring 47 therefore is flushon the outside with the outer boiler plate 45. An inside diameter of thebottom sheet-metal ring 47 is slightly larger than the internal threaddiameter of the thread insert 41, such that the thread insert 41 restson the bottom sheet-metal ring 47. Toward the inside, the inner boilerplate 44 has guiding ribs, which are not shown in the drawing.Complementary to these guiding ribs, an outer wall of the thread insert41 has guide grooves extending in an axial direction, that is to say inthe direction of the axis 49 of FIG. 6. This complementary connectionrepresents an anti-rotation locking mechanism of the thread insert 41relative to the thread carrier 40 about the axis of rotation 49.

The top sheet-metal ring 48 has an outside diameter that corresponds tothe outside diameter of the outer boiler plate 45. The top sheet-metalring 48 therefore is flush toward the outside with the outer boilerplate 45. The top sheet-metal ring 48 has internal threads 50 thatextend in an axial direction, that is to say parallel to the threadedrod 22 in the assembled state of the sheet metal ring 48, into whichinternal threads self-locking bolts 51 are screwed. A collar piece of alocking plate 51 a is fixed between heads of the self-locking bolts 51and the top sheet-metal ring 48. The locking plate 51 a locks in placethe axial position of the thread insert 41 relative to the threadcarrier 40.

The thread carrier 40 accommodates the thread insert 41 and locks samein place. Additionally, it transmits the force from the thread insert 41to the bolts 42, 43.

The thread insert 41 is made of bronze.

The bolts 42, 43 have a cross-sectional step that subdivides each bolt42, 43 into an inner bolt section, which is arranged adjacent to thethread insert 41, and an outer bolt section. The inner bolt section hasa smaller outside diameter than the outer bolt section of the bolts 42,43. The bolts 42, 43 are inserted with the inner bolts sections thereofinto the bores 46 of the boiler plates 44, 45. A sleeve 52 is arrangedin each case between these bores 46 and the inner bolt section.Surrounding and resting against the outer bolt sections of the bolts 42,43 in each case is first a sleeve 53 and surrounding the sleeve 53 ineach case is a guiding body 54.

The sleeves 53 are pressed into the guiding bodies 53 surrounding sameand secured on the respective bolts 42, 43. Serving this purpose in eachcase are locking rings. A wearing disk 55 is inserted between the threadcarrier 40, that is to say the outer boiler plate 45, and the outer endwall of the sleeve 52 on one hand and an inner end section of the sleeve53 on the other hand. On rotational displacement of the guiding body 54relative to the thread carrier 40 about a bolt axis 56 extendinghorizontally in FIG. 6 a defined wear and tear is effected there owingto the wearing disk 55.

In the movement that is driven by the adjustment drive 20 the lower link12 is pivoted about the crawler-support lower pivot shaft 13. The leverend 26 of the lower link 12 thus performs a circular arc-shaped motionof travel. The nut 24 connected to the lever end 26, in turn, performs alinear movement longitudinal to the threaded rod 22. The lever end 26accordingly cannot be connected fixedly to the nut 24. The transmissionof force between the nut 24 and the lever end 26 is effected by means ofa guiding mechanism 57, details of which are shown in FIGS. 7 and 8. Theguiding mechanism 57 is a linear guiding mechanism and is designed inthe form of a roller-type connection. A top end wall 58 and a bottom endwall 59 of the guiding body 54 each run on a roller unit 60, 61 of theguiding mechanism 57. Each of the roller units 60, 61 has a plurality ofbearing rollers 62, six in each case in the presented embodiment. Thebearing rollers 62 of the top roller unit 60 are supported in a topbearing cage 63 and the bearing rollers 62 of the bottom roller unit 61are supported in a bottom bearing cage 64. The bearing cages 63, 64 arefixedly connected to the lever end 26 of the lower link 12 via holdingcomponents 65 that are wedge-shaped in the section of FIG. 7.

When the lever end 26 is shifted longitudinally to the threaded rod 22for pivotally displacing the lower link 12, this goes hand in hand, inparticular near the top and bottom end of the total pivot range, with alinear relative movement of the guiding body 54 relative to the bearingcages 63, 64 longitudinal to a direction of movement marked in FIG. 8with a double arrow 66. The guiding mechanism 57 ensures that thisrelative movement takes place in a guided manner, at the same timeenabling a very high force to be transmitted between the guiding body 54and the roller units 60, 61, and via same and the holding component 65to the lever end 67. At the same time the guiding body 54 isrotationally displaced about the central bolt axis 56 during thismovement.

What is claimed is:
 1. A crawler crane comprising: two crawler supportshaving rotating crawlers, at least one transversal bridge connecting thetwo crawler supports, a crane structure having at least one crane boomconnected to the transversal bridge, a pivot articulation that pivotallyconnects the transversal bridge to the crane structure, wherein at leastone of the crawler supports is connected to the transversal bridge via adouble link comprising: a lower link that is articulated on the crawlersupport via a crawler support lower pivot shaft and on the transversalbridge via a transversal bridge lower pivot shaft, an upper link that isarticulated on the crawler support via a crawler support upper pivotshaft and on the transversal bridge via a transversal bridge upper pivotshaft, and an adjustment drive for pivotally displacing at least one ofthe upper and lower links about at least one of the pivot shafts withwhich said link is articulated to the crawler support and thetransversal bridge, said adjustment drive being directly connected toand providing leverage to the at least one of the upper and lower links,wherein said double link controls compensation of a roll inclination ofthe crawler support about an axis longitudinal to a driving directiondefined by the two crawler supports, wherein the mutual distance betweenthe crawler support lower pivot shaft and the transversal bridge lowerpivot shaft is virtually equal but unequal to the mutual distancebetween the crawler support upper pivot shaft and the transversal bridgeupper pivot shaft, wherein the crawler crane further comprises a controldevice that is in signal connection with the at least one adjustmentdrive, wherein the crawler crane further comprises an inclination sensorthat is in signal connection with the control device, wherein thecrawler crane further comprises a regulating module that is in signalconnection with the control device and with the inclination sensor andprovides to the control device positioning signals for adjusting anadjustment motor in such a way that if the roll inclination of thecrawler support is present, the vertical axis of the crane structureassumes a minimal angle relative to the vertical.
 2. The crawler craneas claimed in claim 1, wherein two double links are provided and whereinboth crawler supports are each connected to the transversal bridge viaone of said double links.
 3. The crawler crane as claimed in claim 2,wherein the double links of both crawler supports each have theadjustment drive for pivotally displacing at least one of the two linksabout the crawler support pivot shaft assigned to same.
 4. The crawlercrane as claimed in claim 1, wherein the lower link is connected to theadjustment drive.
 5. The crawler crane as claimed in claim 1, whereinthe adjustment drive has a threaded rod connected to the crawler supportand a nut connected to the driven lower link, the nut beingcomplementary to the thread of the threaded rod.
 6. The crawler crane asclaimed in claim 5, wherein the threaded rod has a trapezoidal externalthread and the nut has a trapezoidal internal thread complementarythereto.
 7. The crawler crane as claimed in claim 5, wherein thethreaded rod is driven by means of the adjustment drive.
 8. The crawlercrane as claimed in claim 6, wherein the threaded rod extendsperpendicular to a foot print plane, wherein the foot print plane isdefined by a bottom tread of the crawler resting on the ground.
 9. Thecrawler crane as claimed in claim 6, wherein the threaded rod isconnected to the crawler support by means of an axial/radial bearing.10. The crawler crane as claimed in claim 9, wherein the axial/radialbearing is fixedly connected to the crawler support in a manner so as tobe able to rotate about a longitudinal axis of the threaded rod.
 11. Amethod for fine-tuning a basic operating position of a crawler crane,wherein said crawler crane, comprises two crawler supports havingrotating crawlers, at least one transversal bridge connecting the twocrawler supports, a crane structure having at least one crane boomconnected to the transversal bridge so as to be able to pivot about avertical axis, a pivot articulation that pivotally connects thetransversal bridge to the crane structure, wherein at least one of thecrawler supports is connected to the transversal bridge via a doublelink comprising a lower link that is articulated on the crawler supportvia a crawler support lower pivot shaft and on the transversal bridgevia a transversal bridge lower pivot shaft, an upper link that isarticulated on the crawler support via a crawler support upper pivotshaft and on the transversal bridge via a transversal bridge upper pivotshaft, wherein the mutual distance between the crawler support lowerpivot shaft and the transversal bridge lower pivot shaft is virtuallyequal but not equal to the mutual distance between the crawler supportupper pivot shaft and the transversal bridge upper pivot shaft and anadjustment drive for pivotally displacing at least one of the upper andlower links about at least one of the pivot shafts with which said linkis articulated to the crawler support and the transversal bridge,wherein the adjustment drive has a reduction gear, said adjustment drivebeing directly connected to and providing leverage to the at least oneof the upper and lower links, wherein said method comprises thefollowing steps: moving an undercarriage with the two crawler supportsinto a raw operating position, measuring the roll inclination angle ofthe crawler support relative to the vertical of at least one of thecrawler supports, and adjusting the adjustment drive responsive to themeasured roll inclination angle of the crawler support in such a waythat the vertical axis of the crane structure assumes a minimal anglerelative to the vertical, wherein said double link enables compensationof a roll inclination of the crawler support about an axis longitudinalto a driving direction defined by the two crawler supports, furthercomprising the method step of directly engaging the adjustment drivewith the at least one of the two links to pivotally displace the atleast one of the two links about the at least one of the pivot shafts.12. A method as claimed in claim 11, wherein the crawler crane comprisesa control device that is in signal connection with the at least oneadjustment drive and wherein the crawler crane further comprises aninclination sensor that is in signal connection with the control device,wherein the measuring of the inclination angle is carried out using theinclination sensor.
 13. The crawler crane as claimed in claim 1, whereinthe adjustment drive has a reduction gear.
 14. The crawler crane asclaimed in claim 13, wherein the reduction gear has at least three gearwheels that are in combing engagement with one another, the axes ofrotation of which are parallel to one another.
 15. A crawler cranecomprising: two crawler supports having rotating crawlers, at least onetransversal bridge connecting the two crawler supports, a cranestructure having at least one crane boom connected to the transversalbridge, a pivot articulation that pivotally connects the transversalbridge to the crane structure, wherein at least one of the crawlersupports is connected to the transversal bridge via a double linkcomprising: a lower link that is articulated on the crawler support viaa crawler support lower pivot shaft and on the transversal bridge via atransversal bridge lower pivot shaft, an upper link that is articulatedon the crawler support via a crawler support upper pivot shaft and onthe transversal bridge via a transversal bridge upper pivot shaft, andan adjustment drive for pivotally displacing at least one of the upperand lower links about at least one of the pivot shafts with which saidlink is articulated to the crawler support and the transversal bridge,said adjustment drive being directly connected to and providing leverageto the at least one of the upper and lower links, wherein said doublelink controls compensation of a roll inclination of the crawler supportabout an axis longitudinal to a driving direction defined by the twocrawler supports, wherein the adjustment drive is exclusively attachedto the lower link at a lever end, wherein the lever end being locatedopposite the transversal bridge lower pivot shaft, wherein the crawlersupport lower pivot shaft lies between the lever end and the transversalbridge lower pivot shaft, wherein the adjustment drive directly engagesthe at least one of the two links to pivotally displace the at least oneof the two links about the at least one of the pivot shafts.
 16. Acrawler crane comprising two crawler supports having rotating crawlers,at least one transversal bridge connecting the two crawler supports, acrane structure having at least one crane boom connected to thetransversal bridge, a pivot articulation that pivotally connects thetransversal bridge to the crane structure, wherein at least one of thecrawler supports is connected to the transversal bridge via a doublelink comprising: a lower link that is articulated on the crawler supportvia a crawler support lower pivot shaft and on the transversal bridgevia a transversal bridge lower pivot shaft, an upper link that isarticulated on the crawler support via a crawler support upper pivotshaft and on the transversal bridge via a transversal bridge upper pivotshaft, and an adjustment drive for pivotally displacing at least one ofthe upper and lower links about at least one of the pivot shafts withwhich said link is articulated to the crawler support and thetransversal bridge, said adjustment drive being directly connected toand providing leverage to the at least one of the upper and lower links,wherein said double link controls compensation of a roll inclination ofthe crawler support about an axis longitudinal to a driving directiondefined by the two crawler supports, wherein the mutual distance betweenthe crawler support lower pivot shaft and the transversal bridge lowerpivot shaft is virtually equal but unequal to the mutual distancebetween the crawler support upper pivot shaft and the transversal bridgeupper pivot shaft, wherein the adjustment drive directly engages the atleast one of the two links to pivotally displace the at least one of thetwo links about the at least one of the pivot shafts.